摘要：Survivin, a newly discovered member of the inhibitor of apoptosis protein (IAP) family, is over-expressed in tumor and embryonic tissues, but its expression and function in normally differentiated and maturated tissues is rarely reported. The differential expression of survivin in different differentiation stages of dendritic cells (DC), which play an important role in immune tolerance, was explored in the present study. Bone marrow cells were isolated and harvested as DC precursors. Scanning electron microscopy was adopted to observe DC morphology, flow cytometry to identify DC phenotype and mixed lymphocyte reaction (MLR) to compare the ability of DC stimulating allogeneic T cell proliferation. Survivin expression in different differentiation stages of DC was detected. Scanning electron microscopy displayed all different differentiation stages of cells showed typical DC morphology. Flow cytometry showed high expression of CD11c, a relatively specific marker of mouse marrow-derived DC(mDC); CD40, CD86 and MHC-II showed high expression on rmTNF-α-stimulated DC, and MLR revealed the ability of stimulating allogeneic T cell proliferation was also stronger. RT-PCR and Western-blotting assay showed that relative repressions of survivin mRNA and protein in DC precursors, imDC and mDC were 0.3654±0.0702 and 0.1228±0.0162, 0.5582±0.0213 and 0.1443±0.0139, 0.7537±0.0415 and 0.3911±0.0298, respectively (P<0.05). Under different induction conditions, survivin expression varied, and showed an ascending trend with the differentiation and maturation of DC. Inhibition of survivn expression in DC could induce immature dendritic cells (imDC) with immune tolerance.
